What countries have the worst rivalries?

ARE YOU all serious? All the countries you listed have never gone war with each other, it is all diplomatic confrontations. The worst rivalries are in Africa, where they go at it everyday, warring each other. Ethiopia Vs Eritrea, recently in 1999-2001, killing a half million people from both sides using 21century weapons. Look at the Middle-East. Israel-Lebanon. YOU ALL GOT JOKES, referring to peaceful confrontations as a "worst rivalries", ask me about it, because I fought real wars, from child soldier to a refugee camp.